Back support



FIG. 1 is a front perspective view of a back support showing my newdesign;

FIG. 2 is a front view thereof;

FIG. 3 is a right side view thereof, the left side view being a mirrorimage of FIG. 3;

FIG. 4 is a bottom view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a cross-sectional view thereof as seen along line VI-VI inFIG. 2;

FIG. 7 is a rear perspective view thereof; and,

FIG. 8 is a cross-sectional view thereof as seen along line VIII-VIII inFIG. 2.

CLAIM The ornamental design for a back support, as shown and described.